1. Field of the Invention
The present invention relates to an emergency power supply, in particular to a power supply that provides power conversion in normal power conditions and emergency power in case of power outage.
2. Description of Related Arts
Electrical power is not only the key issue to the fast industrial development, but is also an indispensable power source for households. While AC power is mostly used by industrial users which have their different voltage requirements, DC power is used in sensitive equipment, computers, and small electrical appliances. Normally, AC power supply has to be stepped down and converted to DC before the electrical energy can be used to drive these appliances, or alternatively, battery power can be used. It is known that power supply is needed to operate most computers and electronic equipment, and for most people the experiences of power blackouts or brownouts are not uncommon. These abnormal power conditions often cause disruptive loss of data and system interruption for power users without any warning. For sensitive equipment, that means the operation parameters have to be adjusted or reset besides any loss of important data. Many so-called uninterrupted power supply (UPS) devices or backup batteries for power supply management have been designed to fill these needs. Most devices of this kind act as a buffer in a sudden power break, providing power users with additional time so that they can save their valuable operation data and prepare for normal equipment shutdown. But the designs for most devices are quite complex and their applications are limited.
The main object of the present invention is to provide an emergency power supply with simple construction, yet possessing the battery charging/discharging and normal power conversion functions.
The emergency power supply mainly comprises a rectifier component, a stabilizer, a storage battery, a system control circuit, a microprocessor, a DC to DC converter, a voltage booster component, and a pilot light.
The rectifier component is to step down the input voltage and rectify the input AC current from the primary power line; the stabilizer is to provide a constant DC current for battery charging and power conversion; the system control circuit under the control of a microprocessor is to initiate the system control functions; the microprocessor through the output of the rectifier component is to detect any breakage in the primary power supply; the voltage booster component is used to step up the output voltage from the storage battery before passing on to the DC to DC converter; and the DC to DC converter is used to output load current.
In a normal operation cycle, an AC power input having been stepped down is used to charge the storage battery at a constant voltage, and it can also supply the output load current through the DC to DC converter. In case of power outage, the microprocessor detects the abnormal power condition from the rectifier output and enables the switching element to allow current output from the storage battery which is stepped up and passed to the DC to DC converter for supplying the operating loads, such that all emergency initiation procedures are completed before the primary power line is down.
The emergency power supply also includes a temperature sensing circuit for monitoring the operating temperature of the control system and the measured data are output to the microprocessor for system analysis.
The emergency power supply also includes a pilot light formed by two transistors respectively connected to two light emitting diodes of different colors for distinguishing the power status between the primary power and the battery power.